PDF/UA

PDF/UA (PDF/Universal Accessibility, ISO 14289) is the international standard for accessible PDF documents. The version Silktide validates against is PDF/UA-1.

Where WCAG describes accessible web content in general, PDF/UA specifies exactly what an accessible PDF file must contain: a complete tagged structure, a defined reading order, text alternatives for images, machine-readable text, document metadata such as a title and language, and more.

Because its requirements are precise and file-based, PDF/UA conformance can be checked mechanically. Silktide validates documents against PDF/UA using the Matterhorn Protocol as the test checklist, reports each failed requirement, and validates again after remediation so you can see exactly what was fixed.

Find out more

• PDF/UA (ISO 14289) - PDF Association overview of the standard
• ISO 14289-1:2014 - the formal ISO publication
• Matterhorn Protocol
• PDF standards coverage - how Silktide covers each requirement